1. Field of the Invention
The present invention relates generally to a semiconductor device and a method of fabricating the same. More particularly, the present invention relates to an improved method for fabricating a cell contact for DRAM devices.
2. Description of the Prior Art
As known in the art, dynamic random access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. DRAM is usually arranged in a rectangular array of charge storage cells consisting of one capacitor and transistor per data bit.
Normally, each transistor of a DRAM cell comprises a gate, a drain region in a semiconductor substrate, and a source region spaced apart from the drain region. The gate is typically electrically connected to a word line. The source region is typically electrically connected to a digit line. The drain region is typically electrically connected to a capacitor through a cell contact structure.
Continued demand to shrink devices has facilitated the design of DRAM cells with greater density and smaller feature size and cell area. The dimension of the cell contact structure also shrinks dramatically, resulting in increased contact resistance and reduced process window. Damage to the active area (AA) during cell contact etching becomes problematic.
Therefore, there is a need in this technical field to provide an improved method for fabricating a cell contact for DRAM devices, which is capable of avoiding the above-mentioned prior art issues without increasing the complexity of the fabrication process.